Experimental and Theoretical Characterization of the Oxygen-Coordinated Donor−Acceptor Adducts of COCl₂, COClF, and COF₂with AsF₅and SbF₅

Abstract

When reacted with an excess of the corresponding carbonyl halides, AsF5 and SbF5 form the following 1:1 adducts: COCl2·AsF5, COCl2·SbF5, COClF·AsF5, COClF·SbF5, COF2·AsF5, and COF2·SbF5. All adducts are unstable at ambient temperature, and their dissociation enthalpies were determined from the dissociation pressure curves. Vibrational and multinuclear NMR spectra and theoretical calculations show that all compounds are oxygen-coordinated donor−acceptor adducts, and that the strengths of the oxygen bridges increase from COF2 to COCl2 and from AsF5 to SbF5. Full normal coordinate analyses of the adducts demonstrate that the bridging modes occur below 100 cm-1, justifying the frequently used approximation of analyzing similar weak adducts in terms of their separate donor and acceptor molecules.

Structure and Properties of Fumaryl Fluoride

“…[ 12 ] These values are in good agreement with calculated and experimental bond lengths of arsenic pentafluoride adducts. [ 15 ] The bond angles of the AsF 5 –O moiety of the adduct, indicate a slightly distorted octahedral structure. No hydrogen bonds are observed in the crystal structure of 5 .…”

Medium and high oxidation state metal/non-metal fluoride and oxide–fluoride complexes with neutral donor ligands

“…Several carbonyl halides form 1 : 1 adducts with SbF 5 (akin to the AsF 5 analogues above). 391 The reaction of antimony(V) fluoride towards various nitriles including HCN and C 2 N 2 affords the distorted octahedral [SbF 5 (L)], confirmed from the crystal structure of [SbF 5 (C 2 N 2 )]; 408 [SbF 5 (MeSCN)] is also known. 393 The six-coordinate [SbF 5 (NHCCl 2 Mes 2 )] has also been reported.…”

“…390 Various adducts of AsF 5 with inorganic ligands have been characterised: all appear to be six-coordinate. Examples include: [AsF 5 (L)] (L = COCl 2 , COClF and COF 2 ) which are thermally unstable, with stability increasing with chlorine containing substituents; 391 [AsF 5 (S 2 N 2 CO)]; 392 [AsF 5 (MeSCN)]; 393 and [AsF 5 (NMe-(SOF 2 ))] (N-coordinated ligand). 394 Klapo ¨tke and co-workers have reported the preparation of the As(V) complexes, [(AsF 5 ) n (1,3,5triazine)] (n = 1, 2 or 3), by condensing AsF 5 onto a frozen solution of 1,3,5-triazine in SO 2 at À196 1C, following by warming to ambient temperature.…”

Convenient Access to Trifluoromethanol

“…[7,8] However, when anhydrous HF was used as a solvent in these reactions, very different products were obtained. This surprising result prompted us to study the interaction of anhydrous HF with COF 2 in more detail.…”